There is a class of messaging between persons that can be summarized as entailing ‘hand-delivery’, in that the person who sends, gives or receives a message wants to be physically present when a message is received. Prior to electronically-mediated communications, this would be satisfied by the persons involved simply delivering and/or receiving the message in question by hand, thus ensuring the interactional aspect.
The importance of this type of messaging cannot be underestimated. Indeed, this importance even shows itself in common law and everyday language. To ‘shake hands’ over a mutual action is a term that labels both an actual act, a shaking of hands, and a contract that can be, in various ways, legally binding for those whose hands have been shaken. Hand-delivery can also afford less formal benefits. For example, when messages are exchanged by hand, benefit can come from the sender or ‘giver’ seeing the recipient's reaction to the message.
A feature of electronic messaging systems (such as, for example, email, MMS, SMS, etc.) is that they all assume that promptness and certainty of delivery are the primary and often the only aspects of messaging that are significant for both the sender and receiver. The benefits hand-delivery or the contractual and symbolic value of shaking hands at a point of message exchange, are not provided by such electronic messaging systems.
The embodiments described below are not limited to implementations which solve any or all of the disadvantages of known messaging systems.